1. Field of the Invention
This invention relates to improvements in fishing lines formed from high tenacity polyolefin fibers.
2. Description of the Related Art
Fishing lines formed from high tenacity polyolefin fibers are known. Such fibers may be high tenacity polyethylene fibers, such as SPECTRA® extended chain polyethylene fibers and yarns from Honeywell International Inc., as well as other suppliers. Such fishing lines have been commercially successful.
Typically, such high tenacity fibers are made by a spinning a solution containing polyethylene gel swelled with a suitable solvent into filaments of ultrahigh molecular weight polyethylene. The solvent is removed and the resulting yarn is stretched or drawn in one or more stages. In general, such filaments are known as “gel spun” polyolefins, with gel spun polyethylene being the most commercially sold.
Fishing lines from gel spun polyethylene yarns are typically made by braiding multifilament yarns. These fishing lines have advantages over other braided fishing line materials (such as polyesters) as well as nylon monofilament lines, as the ultrahigh molecular weight polyethylene lines have higher strength. However, many anglers prefer the feel of a monofilament fishing line, and braided lines may fray at the end of the line. Also, braided polyethylene lines need to be cut with a shearing device such as a scissor rather than the commonly used compression type line clipper.
It has been proposed in U.S. Pat. No. 6,148,597 to provide polyolefin fishing line that is more monofilament-like in handling. This patent suggests forming braided or twisted yarns and then heating the yarns so that they fuse together. Certain coating materials are suggested to aid in the fusing of the multifilament yarns. The yarns are also subject to a drawing step, with draw ratios of between 1.01 and 2.5 being disclosed.
An improvement on the above technique is described in WO 2006/040191 A1, wherein multifilament yarns are drawn at a ratio of at least 2.7. The result is said to be a fishing line having improved properties such as higher elongation at break.
Fishing lines which are colored are preferred by many anglers. Heretofore, this has been achieved by introducing the braided or twisted yarn into a coating bath containing a colorant. However, it has been found that the colored coating tends to come off with vigorous rubbing. It would be desirable to provide a monofilament polyolefin fishing line that had improved color fastness.